title: A low rate of reinfection following effective therapy against Helicobacter pylori in a developing nation (China).
abstract: OBJECTIVE
  In developed countries, reinfection after successful eradication of Helicobacter pylori appears unusual. High prevalences of H. pylori in developing countries may result in high reinfection rates. The aim of this study was to determine the rate of reinfection and ulcer recurrence in Chinese patients cured of H. pylori and duodenal ulcer disease.
  
  
  METHODS
  One hundred eighty-four patients with duodenal ulcer disease shown by endoscopic examination (1 month) and 14C-urea breath test (3 months) after termination of treatment to have cleared their H. pylori were investigated. Patients were followed up by endoscopy (12 and 24 months) and breath test (6, 9, 12, 18, and 24 months). H. pylori status at endoscopic examination was determined by rapid urease, histology, and culture. In reinfected patients, random amplification of polymorphic DNA fingerprinting was used to compare isolates before and after therapy.
  
  
  RESULTS
  Four patients were reinfected with H. pylori over 24 months (3 within 6 months and 1 at 24 months; average annual recurrence rate, 1.08%). Fingerprinting of isolates from 3 patients showed 1 patient (6 months) to have identical strains and the remainder to have nonidentical strains before and after treatment. Ulcer relapse occurred in 6 patients (4 H. pylori positive).
  
  
  CONCLUSIONS
  Reinfection with H. pylori is rare in developing countries where treatment is effective.
authors.affiliation: School of Microbiology and Immunology, University of New South Wales, Sydney, Australia.
authors.forename: H M
authors.initials: HM
authors.lastname: Mitchell
authors.forename: P
authors.initials: P
authors.lastname: Hu
authors.forename: Y
authors.initials: Y
authors.lastname: Chi
authors.forename: M H
authors.initials: MH
authors.lastname: Chen
authors.forename: Y Y
authors.initials: YY
authors.lastname: Li
authors.forename: S L
authors.initials: SL
authors.lastname: Hazell
mesh_terms: D000328:Adult; D000368:Aged; D002681:China; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000302:isolation & purification; D003906:Developing Countries; D004381:Duodenal Ulcer / Q000382:microbiology* / Q000628:therapy; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence
chemical_list: D004269:DNA, Bacterial